Abstract

The ability of naked mole-rats, Heterocephalus glaberto discriminate between familiar and unfamiliar conspecifics and their response to intruders was investigated. Odour cues used by mole-rats in recognition contexts were identified in a three-way choice apparatus and ‘decision rules’ for accepting or rejecting conspecifics were explored in a series of odour manipulation experiments. Naked mole-rats were highly xenophobic, even to closely related foreign conspecifics, and a division of labour existed amongst the non-breeders in colony defence. The principal mechanism of recognition appeared to be distinct colony odour labels, contributed by each colony member and distributed among, and learned by, all colony members. Differences in the mixture of these odours may provide even genetically similar colonies with a unique odour label. These odours persisted despite controlling for exogenous cues. Fitness consequences of these phenomena are interpreted with respect to the need for closely related neighbouring colonies to maintain autonomy and the importance of excluding foreign competitors from within-colony rivalry for reproductive succession.